whats the usdm itr collector size
as well as the itr cat inlet
i'm comparing to my ls oem header....

thanks in advance

 

2.25" OD

 

The collector size is the same as the LS header. I thought for sure it was 2.0" OD

 

Is the OD 2.0"? I thought that was the ID...

 

OD = Outside diameter

So does that mean I probably won't gain any horses beacause it's the same size as the LS.

whats inner diameter then

& is that a fact, that itr n LS header have the same size collector????

 

All standard aftermarket headers like DC, Comptech, Greddy, Neuspeed, etc. are the same size as stock unless you are looking to one of the big 2.5" JDM headers.

EDIT: The increase in performance is mostly due to the better shape, not bigger size. If bigger size is what made performance you wouldn't get anything out of a standard header upgrade because they are the same size as your stock header. Unless your LS is modified heavily you won't get much out of a JDM 2.5" header other than killing exhaust exit velocity which guts your low end power. Type R's are a different story and will usually do very well with a bigger header on the stock setup.


[Modified by SurferX, 10:40 AM 9/2/2002]

 

thanks for the responses

But the stock LS n stock ITR collector has the same size?

So should I expect any gains if I put the stock itr header on my LS compared to my stock header?

Thanks for the help

 

Like I said it's all the same size. The concept of upgrading to a "bigger" header is in your head. A Type R takes the same aftermarket header as an LS would.

 

So what's the differece between a type R header and an LS header.
both stock oem.

I hope there is & that the ITR is at least a lil better, right?

 

Bumping an old thread...hoping for some specifics....

I just ordered an new ITR b-pipe and Axle back for my LS, since my stock LS b-pipe rusted completely through....since i was ordering the parts i wanted to know, what is the difference between an ITR exhaust Manifold and an LS manifold...i already know the collectors are the same OD and it will bolt up...but what about runner sizes and flow rates?

Will there be ANY better flow through an ITR Exhaust manifold then an LS Exhaust Manifold?

 

The runner sizes between the two are essentially identical, as both the USDM ITR and the LS manifolds use the same top section. The difference is only found in the lower half, where the ITR has a slightly better design. I can't speak to actual measured differences in flow rates, but I can say that the two manifolds are not terribly different from one another. Unless you already have a spare ITR manifold lying around, I'd either stick with the LS manifold or install a quality header instead.

 

Instead of making a new thread I figured I'd post in here. I currently have a greddy exhaust on my ITR. Questions is I'm trying to purchase the JDM ITR B-Pipe and muffler, but I don't know if the pipe will bolt on to my Megan header?

Other option I had in mind is buy the JDM Muffler which I read is 2.5" outlet and weld it to my greddy exhaust. My concern with that is if it will affect my performance? I'm just tired of the loud exhaust daily driving it everywere. I rather get OEM and still keep a good flow, quiet noise, and not affect any performance in the process.

Any advice/help appreciated.

 

This is what I have found out.

Starting at the front.
The USDM header (the distance from the head to the cat) is 7/8" shorter than the JDM's header.
The USDM's outlet (connection point, to the cat) is 1 7/8" id (inside diameter) AKA 2" od (outside diameter).
The JDM is closer to (but not exactly) 2 1/2" id.

Moving to the cat.
The USDM cat is 17 5/8" long and both its inlet and outlet are 1 7/8" id, AKA 2" od.
The JDM cat is 13" long and has matching inlet/outlets, about 2 1/2" od.

To the mid "B" pipe.
The USDM is 4" shorter than the JDM version. The USDM has an 1 7/8" id, AKA 2" od.
I don't have a JDM mid "B" pipe, but I can guess that its diameter will match the JDM cat's outlet diameter, of 2 1/2". Why would Honda choke it?

 

they're the same expect for the lower portion^^ correct

the itr flows better than the bottle necked ls